Batteries are used to provide electrical power in a wide variety of applications. A battery includes one or more electrochemical cells which store energy in chemical form. This stored energy is converted to electrical energy via a redox chemical reaction when an electrical load is connected to the battery. Some batteries are intended for single-use and are discarded after their stored energy is depleted. Such batteries are referred to as primary batteries. Other batteries can be recharged after their stored energy is depleted, and these batteries are referred to as secondary batteries.
One popular secondary battery is a lithium-ion battery, which includes one or more lithium-ion electrochemical cells. Each lithium-ion electrochemical cell includes an anode, a cathode, and electrolyte separating the anode and cathode. Lithium ions move through the electrolyte from the anode to the cathode during cell discharging, and lithium ions move through the electrolyte from the cathode to the anode during cell charging. Lithium-ion batteries advantageously have a high energy density, negligible memory effect, and low rate of self-discharge. However, the batteries have some significant drawbacks.
For example, lithium-ion batteries can be easily damaged by overcharging, potentially resulting in battery leakage, fire, and/or explosion. Therefore, it is critical that the batteries not be overcharged. Additionally, lithium-ion batteries can be damaged when used outside of their intended voltage range. Thus, power management circuitry must ensure that voltage of lithium-ion batteries remains within an acceptable range at all times. Furthermore, the batteries degrade over time, such as due to chemical reactions in the anodes and cathodes of constituent electrochemical cells, resulting in reduced battery capacity and increased likelihood of catastrophic battery failure.